A letter dated June 22, 2015, Les Amis de la Terre France, an NGO working in the field of environment and climate change, addressed the French government, including the President of the Republic, the Prime Minister, and the ministers in charge of the environment and health. The purpose of this letter was to ask the government to take all appropriate measures to reduce–throughout the national territory—concentrations of fine particles and nitrogen dioxide within the limit values set out in Annex XI of Directive 2008/50/EC of the European Parliament and of the Council of 21 May 2008 on ambient air quality and cleaner air for Europe. Subsequently, another letter, dated August 3, 2015, from Les Amis de la Terre France called on the same authorities to design one or more plans relating to air quality, the purpose of which was to define the appropriate measures to reduce—in each of the zones, areas, and agglomerations of the national territory concerned—the concentrations of fine particles and nitrogen dioxide within the limit values set out in Annex XI of the same directive.